This invention relates to a food, and more particularly to a semi-moist food having sugar replaced therein with a corn syrup, and at least one polyhydric component selected from the group consisting of propylene glycol, and 1,3-butanediol.
Within the class of pet foods, there are three general subdivisions -- dry pet food, semi-moist pet food, and moist pet food. Dry pet food generally has a moisture content less than about 15 percent. Semi-moist pet food generally has a moisture content of about 15 to about 50 percent. Moist pet foods generally have a moisture content in excess of about 50 percent. By "moisture content" is meant the amount of water present in the total food composition -- either in combination with one or more of the ingredients in the food or as free water, or combinations thereof.
Among the traditional components of a semi-moist pet food is sugar. Due to economic conditions, replacement of sugar is desirable. However, a sugar replacement is difficult to find because sugar contributes to both the microbiological stability and palatability of the semi-moist pet food. It follows that research is necessary to solve the problem and to find a suitable sugar replacement.
Suitable solutions for solving the problem of a high-priced component, in general, include replacing the component in whole or in part with a more economical component or substitute. This problem is difficult in view of the fact that the substitute must maintain or improve the properties of the composition to which it is being added as compared to the composition containing the original component. Furthermore, the substitute must be cost effective as compared to the original component.
The substitute must permit use of a process that is relatively simple to carry out. In this manner, the cost can be kept down and a suitable nutritious component or product can be provided. Furthermore, the new component must provide or require no substantial changes in the process and be processable. If the process must be changed, the process should be capable of being carried out on the presently available equipment without substantial or difficult modification of that equipment.
Typically a semi-moist pet food having a moisture content in the range of 15 to 50 percent is quite stable and can be stored for long periods of time without sterilization or refrigeration. A major factor in this stable pet food is due to the water soluble solids present in the pet foods having a bacteriostatic affect. Customarily, however, the weight level of the water soluble solids in the food must be greater than that of the moisture. Also, the sugar level must constitute a major percent by weight of the water soluble solids. This high concentration of sugar is undesirable -- especially due to the current economic conditions. The high solute concentration also tends to limit moisture to a maximum of about 30 percent in order to preserve the semi-moist characteristics of the food. It is desirable to increase moisture content and thereby improve palatability, while maintaining microbiological stability.
It is customarily assumed that almost any nonreducing and reducing sugars are equivalent for increasing the osmotic pressure of the water and thereby creating a stabilization effect in a semi-moist pet food. If this assumption of equivalence is correct, reducing and nonreducing sugars can be interchangeable. However, such interchangeability must not provide any other undesirable features. Semi-moist pet foods generally contain animal or vegetable proteins. These proteins in combination with reducing sugars or compounds which contain reducing sugars (such as fructose, isomerose, dextrose and maltose) can cause a non-enzymatic browning reaction known as the Maillard-browning reaction. This reaction takes place between the carbonyl group and nucleophilic groups such as NH.sub.2 to form a Schiff base. This base undergoes further rearrangement and polymerization causing the formation of dark colored compounds. This reaction is undesirable from at least three aspects. Firstly, the product color is unacceptable due to the formation of the high molecular weight compounds. Secondly, the reaction produces an unsuitable odor thereby affecting acceptability of the food. Thirdly, the reaction with the proteins reduces the effective nutrition capability of the proteins. In other words, not only does the appearance suffer from this reaction, but also the acceptability and the nutritional quality of the semi-moist food suffers. For these reasons, reducing sugars, in general, are not suitable equivalents for non-reducing sugar in a semi-moist pet food. If the Maillard-browning reaction and the problems produced thereby can be controlled, a reducing sugar can be used in a food to replace a non-reducing sugar. Technology, however, has yet to solve that problem.
Thus, it is clear that replacement of a sugar component in a food and particularly semi-moist pet food composition has substantial, difficult, research problems connected therewith.